If you are going to rent a house whose paramount purpose is to satisfy your need of permanent housing s.(2) (1) your lease will be governed by Part II (Tenancies for housing) of the Urban Tenancies Act which provides in its section 8 for the assignment of the lease and sub lease
(1) The lease shall not be assigned by the tenant without the landlord’s written consent. In the event of assignment, the assignee is subrogated to the position of the assignor.
(2) The rented house can only be sublet partly and with the prior written consent of the landlord.
Sub-leasing is governed by the provisions of this Part when the sublet part of the dwelling is used by the subtenant to the purpose specified in section 2 (1). Failing this condition, it shall be governed by what has been agreed between the parties.
The right of the subtenant will terminate in any event, when the tenancy of the lessor that subleased terminates.
The rent of the sublease may not exceed, in any case the rent which corresponds to the lease.
If you are not going to use the rented property as a permanent residence your lease will be regulated by Part III of the Act (tenancies for other uses than housing). Whereas tenancies included in Part II are subject to its provisions, failing that by the will of the parties, leases for uses other than housing are regulated by the will of the parties and failing that by Part III of the Act.
The estate agent is simply informing you about a requirement of the landlord, he or she wants 11 months in advance.
You should read carefully the agreement and specially the assignment or sub-lease terms, if there is nothing established about that, then section 32 - which is more designated for business rental - will be applied
32 Assignment of the contract and subletting
(1) If in the leased dwelling-house were ran a business or practiced a professional activity, the tenant can sublet the dwelling or assign the lease without the need to have the consent of the lessor.
(2) The landlord has the right to increase the rent in effect by 10 per cent in the event of a partial sublease, and by 20 per cent in the event of assignment of the lease or the total sublease of the leased dwelling-house
(3) The change in the person of the tenant as a result of a merger, conversion or demerger of the lessor company shall not be deemed as assignment, but the landlord shall be entitled to increase the rent provided in the preceding subsection.
(4) Both the assignment and subleasing shall be properly notified to the lessor within one month since they were entered into.